Catalytic combustion of ammonia-oxygen mixtures



Patented A r. 24, 1928.

UNITED STATES PATENT OFFICE.

Ivan. warm-n11) cannnnnno, or srzomrz, um Baum, ennumJ I CATALYTIC COMBUSTION OF AMMONIA-OXYGEN MIXTURES.

No Drawing, Application filed December 8, 1924, Serial 1T0. 754,655, and in Germany December 4, 1883.

The catalytic combustion of ammonia 10 explosive when ithas a high ammonia content.

Now attempts have already been made to remove these difficulties in various ways, thus for example by means of special cona so high drop of temperature is created between the catalyst and the apparatus walls, that explosions are prevented. Under these reaction conditions the occurrence of flame combustion in the interior of the contact apparatus is not possible. On the other hand and surprisingly enough "no cessation of the flameless catalytic combustion takes place in spite of the very intense cooling.

The process permits of aperfectly safe combustion of ammonia-oxygen mixtures with almost the theoretical yield of nitric oxides.

I claim 2o dustrial working the means hitherto em- 1. In the process of catalyticallyoxidizing ammonia to nitric oxides, the step which comprises passing a mixture of ammonia and oxygen over a catalyst heated to reaction temperature and maintained in a reaction zone, and cooling one, face of the reaction zone whereby a high temperature 15 structions of the apparatus, by cooling the gaseous mixture before admitting it to the reaction chamber, or by cooling the contact apparatus itself.

It has however been found that in inployed for obviating over-heating of the catalyst do not succeed in producing, in the gradient is formed between the catalyst and case of gaseous mixtures with a high amthe cooled face. nionia content, an oxidation of the ammonia 2. In the process of oxidizing ammonla 25 without loss. Novg the invention consists to n itricoxide, 1n acatalytic chambercon- C in this, thatthe reaction mixture containing taming a catalyst heated to reaction temammonia and oxygen is conducted over a perature, the step whlch comprises cooling catalyst at which all parts are directly enthe walls of sa d chamber so that a temperaclosed by the apparatus walls and that by ture gradlent is effected betweenthe heated 30' cooling the contact a paratus by means of catalyst and the walls of the container.

IVAR WALFRID CEDERBERG.

a suitable cooling fluld, for instance water, 

